Air compression arrangement for vehicles

ABSTRACT

The invention relates to an arrangement for a compressed-air system ( 1 ) in a vehicle, comprising a connection ( 6, 10 ) for feeding compressed air from a compressor ( 2 ) to the rest of the compressed-air system. The invention is characterized in that it comprises an oxidation catalyst ( 9 ) which is adapted for cleaning the compressed air and which is positioned along said connection ( 6, 10 ), said connection ( 6, 10 ) comprising a line ( 10 ) which is connected between the oxidation catalyst ( 9 ) and the rest of the compressed-air system. The invention provides an improved arrangement for cleaning compressed air in a compressed-air system for a vehicle.

This application is the national phase under 35 U.S.C. § 371 of PCTInternational Application No. PCT/SE00/00638 which has an Internationalfiling date of Apr. 4, 2000, which designated the United States ofAmerica and was published in English.

TECHNICAL FIELD

The present invention relates to an arrangement for a compressed-airsystem in a vehicle. The invention is intended in particular for use incompressed-air systems in heavy-duty lorries.

BACKGROUND ART

In connection with a vehicle which is provided with a compressed-airsystem for producing, storing and distributing compressed air to, forexample, the air suspension system and the brake system, which in amanner known per se includes pressure tanks, compressed-air lines andvarious types of valve, said system is supplied with compressed air froma compressed-air compressor. Said compressor is driven in a manner knownper se by means of the internal combustion engine of the vehicle. Tolubricate the compressor, use is made, according to the known art, oflubricating oil from the lubricating oil system of the internalcombustion engine.

In accordance with previously known art, the compressed air can be fedfrom the compressor to the compressed-air system of the vehicle. Aproblem which occurs in previously known compressed-air systems of theabovementioned type is that the compressed air which is generated in thecompressor is often contaminated by lubricating oil in aerosol andgaseous form. During operation of the compressor, a very hightemperature is reached, which can lead to oxidation of the lubricatingoil mixed into the compressed air, which can result in polymerization ofthe oil and the formation of aggressive oxidation products. If thesecontaminants were to be conveyed to the rest of the compressed-airsystem of the vehicle, coatings could be formed in the components ofsaid system. These coatings can cause clogging and corrosion of thematerial of said components, which can in turn cause failure of thecomponents.

According to the known art, the compressed air generated in thecompressed-air compressor can be cleaned by means of a mechanical filtercombined with cooling. A disadvantage of this technique, however, is itslow degree of efficiency.

DISCLOSURE OF INVENTION

The object of the present invention is to provide an arrangement forefficient cleaning of compressed air in a compressed-air system for avehicle, in particular for a compressed-air system in which thecompressed air is generated by a compressor which is lubricated bylubricating oil from an internal combustion engine.

The invention constitutes an arrangement for a compressed-air system ina vehicle and comprises a connection for feeding compressed air from acompressor to the rest of the compressed-air system. The invention ischaracterized in that it comprises an oxidation catalyst which isadapted for cleaning the compressed air and which is positioned alongsaid connection, said connection comprising a line which is connectedbetween the oxidation catalyst and the rest of the compressed-airsystem.

Advantageous embodiments of the invention emerge from the dependentpatent claims below.

BRIEF DESCRIPTION OF DRAWINGS

The invention will be explained in greater detail below with referenceto a preferred illustrative embodiment and the appended FIG. 1 which isa basic diagram of an arrangement according to the present invention.

MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a basic diagram of an arrangement according to the presentinvention. According to a preferred embodiment, the arrangement is usedin connection with a compressed-air system 1 of a type known per se,which may preferably but does not have to consist of a compressed-airsystem for a lorry. The compressed-air system 1, which comprises, forexample, a pressure tank and also the air-suspension system and thebrake system of the vehicle, is reproduced in a greatly simplifiedmanner in FIG. 1.

Compressed air in the compressed-air system 1 is generated in acompressor 2 which is mechanically connected to an internal combustionengine 3 via a transmission 4. In this way, the air flowing from theatmosphere, as indicated by an arrow in the figure, and to thecompressor 2 via an air intake line 5, can be compressed and fed out ina line 6. The compressor 2 is supplied with lubricating oil from thelubricating oil system 7 of the internal combustion engine 3 via aseparate line 8 which is connected to the compressor 2.

When the compressor is in operation, a very high temperature isgenerated in it, which causes oxidation of the lubricating oil mixedinto the compressed air. The aggressive oxidation products then formed,for example esters, resin-like substances and aerosols, can contaminatethe compressed air generated in the compressor 2. If this contaminatedcompressed air were to be fed to the compressed-air system 1, it couldform coatings on pressure tanks and the like and bring about clogging ofvalves and material corrosion. For this reason, it is a fundamentalprinciple of the present invention that the contaminated compressed airis led from the compressor 2 to an oxidation catalyst 9 via the line 6connected to it from the compressor 2. In the oxidation catalyst 9, thecontaminants contained in the compressed air will be converted to carbondioxide and water. The cleaned compressed air is then conveyed to thecompressed-air system 1 by means of another line 10.

The oxidation catalyst 9 is designed in such a manner that it has agiven minimum limit temperature at which it is capable of working withsatisfactory cleaning capacity. This limit temperature is usually of theorder of roughly 200° C. In order to guarantee the desired limittemperature, the invention can be adapted so that the oxidation catalyst9 comprises heating means. This can in turn be brought about by theoxidation catalyst 9 being designed with an electric heatingarrangement, in which way it is possible to ensure that the desiredtemperature of the oxidation catalyst 9 can be reached.

It may be pointed out, however, that the correct working temperature isreached in the oxidation catalyst 9 during normal operation of thecompressor 2 without a separate heating arrangement, because thecompressed air generated in the compressor 2 reaches a very hightemperature.

The invention is not limited to the embodiment described above but canbe varied within the scope of the patent claims below. For example, theinvention can be used in different types of vehicle, for example privatecars, lorries, loading machines and buses, which comprise a compressorfor generating compressed air for a compressed-air system.

1. An apparatus for a compressed-air system (1) in a vehicle,comprising: a connection (6,10) for feeding compressed air from acompressor (2) to the rest of the compressed-air system, wherein itcomprises an oxidation catalyst (9) which is adapted for cleaning thecompressed air and which is positioned along said connection (6,10),said connection (6,10) comprising a line (10) which is connected betweenthe oxidation catalyst (9) and the rest of the compressed-air system. 2.An apparatus according to claim 1, wherein the oxidation catalyst (9)can be heated.
 3. An apparatus according to claim 2, wherein theoxidation catalyst (9) can be heated by means of an electric heatingarrangement.
 4. An apparatus according to claim 1 wherein the apparatusincludes an engine (3) consisting of a diesel engine.
 5. An apparatusaccording to claim 2 wherein the apparatus inclues an engine (3)consisting of a diesel engine.
 6. An apparatus according to claim 3wherein the apparatus includes an engine (3) consisting of a dieselengine.
 7. An apparatus according to claim 1 wherein the compressed-airsystem is a brake system.
 8. An apparatus according to claim 1 whereinthe compressed-air system is an air suspension system.
 9. A system for avehicle having an engine for powering the vehicle, comprising: acompressor, that is driven by the engine, for drawing air and supplyingcompressed air to a vehicle mounted compressed-air system; a lubricatingoil system for lubricating the vehicle engine and the compressor; a linefor feeding compressed air from the compressor to the compressed-airsystem; and an oxidation catalyst device, coupled to the line, forcleaning the compressed air which is contaminated by the lubricating oilsystem and for feeding clean air to the remainder of the compressed-airsystem.
 10. A system according to claim 9 wherein the compressed-airsystem is a brake system.
 11. A system according to claim 9 wherein thecompressed-air system is an air suspension system.
 12. A systemaccording to claim 9 wherein the air is drawn into the compressor fromthe atmosphere.
 13. A system according to claim 9 wherein the vehicleengine is a diesel engine.